Barton was as busy outside of the advertising agency as he was in it. Having published several books - mostly collections of essays - by the time BDO was formed in 1919, the freedom and time available to write was certainly a factor in Barton's decision to join in the formation of BDO. Throughout his time at BDO, he continued to write editorials for Redbook for several years. It's a Good Old World, his collection of essays written for Redbook while he was running the new agency, was published in 1920.His most famous book, The Man Nobody Knows, was originally published as serials by Woman's Home Companion. In short, the book offered an earnest interpretation of Jesus as a businessman exemplifying the charisma, poise, and strength needed to succeed. By 1924 he had completed the work, and after a few rejections based on the content of the book, it was finally published. Although not universally approved of, it was a success. By 1926, it had sold as many as a quarter of a million copies. In 1926, it was followed by The Book Nobody Knows, Barton's interpretation of the Bible. In spite of the fact that The Man Nobody Knows was followed by more than half a dozen other books in less than ten years, it remains his best known work.
Due to stress, Barton checked himself into a sanitarium briefly in 1928. The source of the stress was at least partly caused by troubles surrounding an affair with Frances King. Although it is unclear (and probably irrelevant) how long the affair lasted, it ended in 1928. By 1932, Barton was forced to sue Frances King for blackmail surrounding a potentially defamatory although ostensibly fictional book she threatened to publish.